1. Field of the Invention
The present invention relates to a touch operation detection apparatus.
2. Description of the Related Art
In the related art, a touch operation detection apparatus which detects a touch operation of a human being is known (for example, see Japanese Laid-Open Patent Application No. 2011-113188). The known touch operation detection apparatus includes a touch panel of an electrostatic capacitance type touchable by a body of a human being. The touch panel includes a plurality of electrostatic sensors each of which has an electrostatic capacitance varying according to a touch thereto. Each electrostatic sensor outputs a signal according to its electrostatic capacitance. A control part of the touch operation detection apparatus detects the electrostatic capacitance value based on the signal from the electrostatic sensor, and determines whether the touch operation is being made based on the detected electrostatic capacitance value.
The known touch operation detection apparatus activates a calibration circuit and carries out an offset adjustment of replacing the output value of the electrostatic sensor by zero, determining that a touch does not intend a data input as an operation of an operator, when a touch detection time of detecting the touch on an operation surface of the touch panel has become greater than or equal to a predetermined time. Thus, it is possible to avoid an erroneous determination that a touch operation is being made, due to a fact that the operator is unintentionally touching the operation surface by his or her finger, merely a stain or so adheres to the operation surface, or so.